<?php namespace Dotdigitalgroup\Email\Model\Adminhtml\Source\Contact; class Subscriber implements \Magento\Framework\Data\OptionSourceInterface { /** * @return array */ public function toOptionArray() { $options = [ [ 'value' => 'null', 'label' => '' ], [ 'value' => '1', 'label' => 'Subscriber', ] ]; return $options; } }